Desertification: On the Trail of Abandoned Cities

The old city walls of Yinpan, China, are one of the most visible structures that still remain in the area. The dry and parched soil that surrounds them increasingly contributes to the fragility of the site and its unstable existence.

Human remains lie scattered around the old city of Yinpan, China. A combination of erosion and disturbance by grave robbers has left clues to the city's past readily on view to visitors. Yinpan is one of nearly 40 cities that have been abandoned in Northwest China due to desertification.

The remains of a wooden coffin lie in the intense midday heat of Yinpan, China. Dating of different species of wood used in making coffins has allowed Chinese archaeologists to speculate on the age of the abandoned settlement, once a thriving stop along the legendary Silk Road.

In the summer, flash floods wash away what remains of the ancient Chinese city of Yinpan. Seen here is a heavily eroded Buddhist temple.